Australia has rebuffed a plea by the United States to increase its military contribution in Iraq and Syria following the Paris terror attacks.
The news of Australia's resistance comes as prime minister Malcolm Turnbull prepares to make his first visit to Washington as Australia's leader next week.
Defence minister Marise Payne's office said America had asked 40 countries, including European nations, "to consider expanded contributions" to the US-led coalition fighting in the Middle East after the Islamic State (IS) group claimed responsibility for the November 13 attacks on Paris cafes, restaurants, a sports stadium and a music hall that killed 130 people.
"Australia has considered the request from US secretary of defence Ash Carter in light of the substantial contributions we are already making to train Iraqi security forces and to the air campaign," the statement said.
"The government has advised Secretary Carter that our existing contributions will continue."
Australia has offered no significant increase in resources but "the Australian government continues to keep our contribution under ongoing review in consultation with our coalition partners", the statement said.
The controversial reaction to a request for military assistance from its most important security ally has been questioned within the ranks of Mr Turnbull's conservative government.
Sydney's Daily Telegraph newspaper said Mr Turnbull had become the first Australian prime minister to refuse a US request to supply more troops in a conflict zone.
Peter Jennings, executive director of the Australian Strategic Policy Institute think-tank and a former defence department deputy secretary for strategy, said Australia often refused US requests for military help.
"I don't think the Americans will be surprised," he said, but added they may ask "what's going on with this new prime minister in Canberra?".
Mr Jennings said it would be seen in the context of US president Barack Obama chiding Mr Turnbull when they met in Manila in November for failing to warn America of plans to lease a strategically important north Australian port where US Marines are posted to a Chinese company linked to the People's Liberation Army.
Australia under Mr Turnbull has also resisted US pressure to mount a public demonstration of freedom of navigation in the South China Sea.
Mr Turnbull replaced Tony Abbott as prime minister in September and Mr Abbott has since become more hawkish in his statements on military intervention in Iraq and Syria, calling for a greater effort in ground warfare.
Kevin Andrews, who was defence minister in Abbott's last administration, said he did not know on what information Ms Payne had based her decision.
"My general in-principle view is that if the Americans have made a reasonable request of us, then we should be giving it the most favorable consideration," he told Australian Broadcasting Corporation.
US ambassador to Australia John Berry said "the United States is enormously grateful for the role Australia is playing" and Mr Carter had asked for assistance from all 60 nations in the US-led coalition.
Australia describes itself as the largest contributor to the coalition after the United States, with 780 Australian military personnel in the Middle East and aircraft including six F/A-18 Hornet jet fighters striking IS targets in Iraq and Syria.